1. Field of the Invention
The present invention relates to a thermal treatment apparatus that thermally treats a substrate such as a semiconductor wafer, specifically a batch-type thermal treatment apparatus.
2. Description of the Related Art
In a fabrication process of semiconductor devices, a batch-type thermal treatment apparatus, where plural substrates are arranged at predetermined intervals and thermally treated in a batch, is used. Such a thermal treatment apparatus is provided with a reaction tube that has a lower opening, a wafer supporting member that supports plural substrates at predetermined intervals and is accommodated within the reaction tube, and an outer heater that heats the substrates in the reaction tube.
According to the thermal treatment apparatus, the wafer supporting member that supports the plural substrates is transferred into the reaction tube; the substrates are heated by the outer heater; and a process gas is supplied into the reaction tube through a gas supplying nozzle. In such a manner, the plural substrates go through a thermal treatment depending on the process gas.
Patent Document 1: Japanese Patent Application Laid-Open Publication No. 2000-068214